1. Field of the Invention
The present invention relates to a robot cleaner and, more particularly, to an automatic charging system and method of a robot cleaner.
2. Description of the Background Art
FIG. 1 is a schematic block diagram showing a construction of a charging system of a robot cleaner in accordance with a conventional art.
As shown in FIG. 1, a charging system of a robot cleaner (not shown) consists of a power receiving unit 100 of a robot cleaner and a power supply unit 200 for charging a battery 101 of the robot cleaner.
The power supply unit 200 includes an infrared ray sensor 201 for communicating with the robot cleaner and a charging unit 202 for charging the battery 101 of the robot cleaner. The infrared ray sensor 201 is installed at the charging unit 202 and generates an infrared signal in a predetermined direction.
The power receiving unit 100 of the robot cleaner includes: a battery 101; a remaining battery capacity detector 102 for detecting a remaining capacity of the battery 101 installed in the robot cleaner; a infrared ray sensor 103 fixedly installed in the robot cleaner and communicating with the power supply unit 200; and a microcomputer 104 for moving the robot cleaner along a pre-set path through a mapping algorithm in order to receive an infrared signal outputted from the infrared ray sensor 201 of the power supply unit 200 if the detected remaining battery capacity is below a reference value, and moving the robot cleaner to the charging unit 202 on the basis of an infrared ray signal upon receipt of it.
The infrared ray sensor 103 is fixedly installed at the robot cleaner in order to detect the infrared signal of the infrared ray sensor 201 of the charging unit 202.
The infrared ray sensor 103 of the robot cleaner outputs to the power supply unit 200 a start signal for transmitting a data informing that a communication protocol starts for charging to the charging unit 200, a coupler signal for informing that a charge switching unit (not shown) of the robot cleaner is turned on; a complete signal informing that the communication protocol for charging is terminated, and an end signal for informing that charging is ended when an error is generated in the robot cleaner, according to a control signal of the microcomputer 104.
The infrared ray sensor 201 of the power supply unit 200 outputs to the power receiving unit 100 a connection request signal for informing that the charging unit 202 is available for charging, a charge signal for indicating that charging is started, and a fault signal for informing the robot cleaner that there is an error in the charging unit 202, according to a control signal of the charging unit 202.
The operation of the charging system of the robot cleaner will now be described with reference to FIG. 1.
First, when the robot cleaner is in a charging mode, the microcomputer 104 of the robot cleaner moves the robot cleaner along a pre-set path through a mapping algorithm in order to receive an infrared signal.
When the infrared ray sensor 103 of the robot cleaner receives an infrared signal generated from the infrared ray sensor 201 of the power supply unit 200 while the robot cleaner is moved along the pre-set path, the infrared ray sensor 103 outputs the received infrared signal to the microcomputer 104.
Then, the microcomputer 104 moves the robot cleaner to a position of the charging unit 202 on the basis of the infrared signal, generates a start signal through the infrared ray sensor 103, and transmits the generated start signal to the infrared ray sensor 201. Then, the infrared ray sensor 201 of the power supply unit 200 detects the start signal and transmits the connection request signal to the infrared ray sensor 103 of the robot cleaner.
Thereafter, when the microcomputer 104 detects the connection request signal through the infrared ray sensor 103 of the robot cleaner, a power terminal (not shown) of the robot cleaner is electrically connected to a charge terminal (that is, charge plate, not shown) installed at the charging unit 202 according to a control signal of the microcomputer 104.
When the power terminal and the charge terminal are connected to each other (available for charging), the microcomputer 104 transmits the coupler signal to the infrared ray sensor 201 of the charging unit 200 through the infrared ray sensor 103 of the robot cleaner. Then, the charging unit 202 receives the coupler signal through the infrared ray sensor 201, generates the charge signal, and charges the battery 101.
Thereafter, when the battery is completely charged, the microcomputer 104 transmits the complete signal to the infrared ray sensor 201 of the charging unit 202, and upon receipt of the complete signal, the charging unit 202 cuts off the charge signal. As the charge signal is cut off, the coupler signal of the robot cleaner is not generated any longer.
Meanwhile, if the end signal is generated from the robot cleaner or if the fault signal is generated from the charging unit 202 while the battery 101 is being charged, the connection request signal is cut off and the battery charging operation is ended after a certain time lapse.
However, the charging system of the robot cleaner in accordance with the conventional art has the following problems.
That is, in order to receive the infrared signal generated from the infrared ray sensor installed at the charging unit 202, the robot cleaner itself is moved along the pre-set path, so that the robot cleaner fails to quickly move to the charging unit (that is, the charge terminal of the charging unit). In other words, because the robot cleaner is moved along the pre-set path to detect the infrared signal, it can not detect the infrared signal quickly.
In addition, in order to detect the infrared signal quickly, a plurality of infrared ray sensors are fixedly installed at the robot cleaner. Thus, fixedly installation of the plural infrared ray sensors at the robot cleaner to receive the infrared signal outputted from the charging unit within a short time causes an increase in a cost for implementing the charging system of the robot cleaner.